Signal processing for a rear-projection TV using a digital micro-mirror array

A rear-projection TV using a digital micro-mirror array has been developed. This paper describes an overview of its digital signal processing design, and introduces the signal processing techniques applied to the TV system. The digital micro-mirror array is designed for HDTV and has a resolution of 1280×720 pixels. It is required to convert various input signals such as NTSC, HDTV and PC signals to a resolution of 1280×720 pixels. This paper specifically describes the techniques of converting NTSC (480i) signals and presents an outline of the auto-picture-level (APL) control and black-level-expansion (BLE) control using image histogram data. The APL control and BLE control have been adopted for effective use of the limited dynamic range of the brightness. These new techniques have realized high quality conversion of 1280×720 pixels from various input formats, and effective picture enhancement that is most suitable for a digital device